This relates to communication networks, and more particularly, to communications networks having network switches that are controlled by a controller.
Packet-based networks such as the internet and local data networks that are connected to the internet include network switches. Network switches are used in forwarding packets from packet sources to packet destinations. The packets may be sometimes referred to as frames.
It can be difficult or impossible to control the switches of one vendor using the equipment of another vendor. This is because the switch equipment of one vendor may use a different operating system and set of control procedures than the switch equipment of another vendor. To address the challenges associated with controlling different types of switch platforms, cross-platform protocols have been developed. These protocols allow centralized control of otherwise incompatible switches.
Cross-platform controller clients can be included on the switches in a network. The controller clients are able to communicate with a corresponding controller server over network paths. Because the controller clients can be implemented on a variety of switch hardware, it is possible for a single controller to control switch equipment that might otherwise be incompatible.
A network controlled by a controller can be connected to external networks via gateway devices that interface between the network and the external networks. Network packets that are sent from end hosts of the network to end hosts of the external networks are routed through one or more of the gateway devices. It may be difficult for the network packets to be efficiently routed from the network to the external networks. For example, end hosts in the network may have limited information regarding gateways that are available to interface with the external networks.